A Gulf Coast process piping contractor used IronKit to verify their cost-per-foot on 4-inch Schedule 40 carbon steel pipe. The multi-pass weld procedure called for a GTAW root pass at $4.50/ft, a SMAW hot pass at $2.00/ft, and fill/cap passes at $5.50/ft — totaling $12.00/ft installed. The shop previously estimated $10/ft but was consistently losing money on fabrication. IronKit's breakdown revealed the GTAW root was being underpriced: actual arc time at $95/hr for a certified 6G pipe welder produced $4.50/ft, not the $3/ft estimate they'd been using.
Frequently Asked Questions
Why is the GTAW root the most expensive pass?
The GTAW root pass requires the slowest travel speed (precise heat control, keyhole technique) and the highest-paid welder (6G certified). On 4" Sch 40, a good root pass takes 6–8 minutes. At $95/hr pipe rate, that's $9.50–$12.67 per joint, or $4.50–$6/ft.
What is a "hot pass" and why does it cost less?
The hot pass is the first pass over the root — typically SMAW E6010 — applied immediately to maintain temperature and fill the root profile. It's faster than the root and can be done by a journeyman instead of a certified 6G welder on some specs. Hence the lower per-foot cost.
How many fill passes does 4" Sch 40 need?
4" Sch 40 has a 0.237" wall. After the root and hot pass, typically 2–3 fill passes with E7018 are needed before capping. Actual count depends on bead size and electrode diameter.
Does IronKit calculate NDE cost for pipe welds?
Yes. IronKit adds RT, UT, or PT cost as a line item when you specify the NDE requirement. For API 1104 or ASME B31.3, typical 100% RT adds $35–$75 per weld depending on diameter and film cost.